Preparation And Application Of Electrochemical Sensors Based On MOFs-derived Carbon Materials

Electrochemical sensing is an area that has attracted widespread attention and is developing quickly and strongly.Nowadays,with the deepening of electrochemical analysis research,electrochemical sensors are more and more widely used in the detection of disease markers,biological small molecules,environmental pollutants and other organic molecules.Based on the characteristics of easy operation,low cost and high sensitivity of electrochemical devices,electrochemical sensing is widely used in environmental sanitation,medical health and other fields.The development of materials science has promoted the progress of electrochemical analysis.The selection of excellent electrode materials for electrode modification can greatly improve the detection performance of the constructed electrochemical sensor.Metal-organic framework is one of the emerging hot materials.Due to its porosity,high specific surface area,adjustable pore size,versatility,physical and chemical stability,it is used widely in the field of energy conversion and storage(oxygen reduction,electrolyzed water,carbon dioxide reduction,lithium batteries,etc.),biomedical(biosensing,biotherapy,bioimaging),toxic gas detection,gas separation,etc.Due to the porous ordered nature of MOF,organic ligands can provide a rich source of heteroatoms.The carbon material obtained by carbonizing the MOF precursor often inherits the ordered structure characteristics of the precursor MOF and is rich in hetero atom doping.Such a carbon material has a higher specific surface area and better chemical and physical stability than a bulk carbon material having an irregular shape.The constructed sensor is capable of exhibiting superior electrocatalytic activity and detection performance.In this paper,using MOFs-derived carbon materials as electrode materials,three electrochemical sensors were constructed for Acetaminophen(APAP),uric acid(UA)and dopamine(DA)detection.The main experimental contents are as follows:1.Using ZIF-8 as a precursor material,P-NC porous carbon obtained by PVP using an auxiliary limited carbonization ZIF-8 method and was used as the electrode material.The obtained P-NC porous carbon has a pore size hierarchical distribution and an N atom doping characteristic,which is favorable for the improvement of the sensor electrocatalytic ability.The DPV method was used to detect APAP.The constructed P-NC/GCE electrochemical sensor can be used to detect APAP.The detection results have a wide linear detection range,high detection sensitivity,and satisfactory detection limit.The detection limit(LOD)is 0.5 ?M(at an S/N = 3).Also,P-NC/GCE was used to detect APAP in urine samples.Therefore,the P-NC/GCE electrochemical sensor constructed in this work has considerable potential and prospects for detection applications.2.In this work,we developed a novel electrochemical sensor based on N,Co-doped porous carbon(CNCo)that was synthesized via direct carbonization of BMZIF nanocrystals for the first time and used for determination of uric acid in human serum samples.Due to the high surface area,large pore volume,and highly dispersed active sites of CNCo,the fabricated CNCo/GCE electrode exhibited better electrocatalytic activity toward the oxidation of UA and a higher peak current than the bare GCE electrode.Moreover,the CNCo/GCE sensor presented excellent anti-interference ability,long-term stability,good reproducibility,repeatability,and satisfactory recoveries for the detection of UA in real samples.All these results suggest that the proposed method is a potential candidate for analytical applications.3.A simple ratiometric electrochemical method was designed to detect DA.According to previous reports,ZIF-8 derived nitrogen-doped porous carbon(NC)through high-temperature carbonization is easy to catalyze the oxidation of dopamine.After screening,we decided use methylene blue(MB),a thiazine dye commonly used for redox indication as an appropriate internal reference material.The agent serves as an internal reference to provide built-in correction during the test.The methylene blue molecules are immobilized on the surface of the porous carbon by ?-? stacking and hydrophobic interaction to realize functionalization of the electrode material.The obtained self-assembled MB@NC complex was applied to the surface of bare glassy carbon electrode for DA detection.